CZ,
Once a year is probably OK for most things. Ideally some things might be done more often, but that's an ideal. At your mileage, hubs would be about the only thing that might be at the edge of the envelope, but I don't think doing them once a year would cause damage unless you do a lot of dirty riding. Think of all the bikes out there that NEVER get serviced. Obviously, your chain would appreciate being cleaned and lubed every 2-3 weeks.
Regards,
Raymond

Added: You know, until today I have been reading your name as cycles-a-lot. I just realized it's cycle zealot. Doh!